internal/ethapi: add mutex around signing + nonce assignment

This prevents concurrent assignment of identical nonces when automatic
assignment is used.

3 files changed, 92 insertions, 36 deletions

diff --git a/internal/ethapi/addrlock.go b/internal/ethapi/addrlock.go
new file mode 100644
index 000000000..5a9c948b8
--- /dev/null
+++ b/internal/ethapi/addrlock.go
@@ -0,0 +1,53 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package ethapi
+
+import (
+	"sync"
+
+	"github.com/ethereum/go-ethereum/common"
+)
+
+type AddrLocker struct {
+	mu    sync.Mutex
+	locks map[common.Address]*sync.Mutex
+}
+
+// lock returns the lock of the given address.
+func (l *AddrLocker) lock(address common.Address) *sync.Mutex {
+	l.mu.Lock()
+	defer l.mu.Unlock()
+	if l.locks == nil {
+		l.locks = make(map[common.Address]*sync.Mutex)
+	}
+	if _, ok := l.locks[address]; !ok {
+		l.locks[address] = new(sync.Mutex)
+	}
+	return l.locks[address]
+}
+
+// LockAddr locks an account's mutex. This is used to prevent another tx getting the
+// same nonce until the lock is released. The mutex prevents the (an identical nonce) from
+// being read again during the time that the first transaction is being signed.
+func (l *AddrLocker) LockAddr(address common.Address) {
+	l.lock(address).Lock()
+}
+
+// UnlockAddr unlocks the mutex of the given account.
+func (l *AddrLocker) UnlockAddr(address common.Address) {
+	l.lock(address).Unlock()
+}
diff --git a/internal/ethapi/api.go b/internal/ethapi/api.go
index a22c15eca..371786e4a 100644
--- a/internal/ethapi/api.go
+++ b/internal/ethapi/api.go
@@ -23,7 +23,6 @@ import (
 	"fmt"
 	"math/big"
 	"strings"
-	"sync"
 	"time"
 
 	"github.com/ethereum/go-ethereum/accounts"
@@ -204,12 +203,13 @@ func (s *PublicAccountAPI) Accounts() []common.Address {
 // It offers methods to create, (un)lock en list accounts. Some methods accept
 // passwords and are therefore considered private by default.
 type PrivateAccountAPI struct {
-	am *accounts.Manager
-	b  Backend
+	am        *accounts.Manager
+	nonceLock *AddrLocker
+	b         Backend
 }
 
 // NewPrivateAccountAPI create a new PrivateAccountAPI.
-func NewPrivateAccountAPI(b Backend) *PrivateAccountAPI {
+func NewPrivateAccountAPI(b Backend, nonceLock *AddrLocker) *PrivateAccountAPI {
 	return &PrivateAccountAPI{
 		am: b.AccountManager(),
 		b:  b,
@@ -316,10 +316,6 @@ func (s *PrivateAccountAPI) LockAccount(addr common.Address) bool {
 // tries to sign it with the key associated with args.To. If the given passwd isn't
 // able to decrypt the key it fails.
 func (s *PrivateAccountAPI) SendTransaction(ctx context.Context, args SendTxArgs, passwd string) (common.Hash, error) {
-	// Set some sanity defaults and terminate on failure
-	if err := args.setDefaults(ctx, s.b); err != nil {
-		return common.Hash{}, err
-	}
 	// Look up the wallet containing the requested signer
 	account := accounts.Account{Address: args.From}
 
@@ -327,6 +323,18 @@ func (s *PrivateAccountAPI) SendTransaction(ctx context.Context, args SendTxArgs
 	if err != nil {
 		return common.Hash{}, err
 	}
+
+	if args.Nonce == nil {
+		// Hold the addresse's mutex around signing to prevent concurrent assignment of
+		// the same nonce to multiple accounts.
+		s.nonceLock.LockAddr(args.From)
+		defer s.nonceLock.UnlockAddr(args.From)
+	}
+
+	// Set some sanity defaults and terminate on failure
+	if err := args.setDefaults(ctx, s.b); err != nil {
+		return common.Hash{}, err
+	}
 	// Assemble the transaction and sign with the wallet
 	tx := args.toTransaction()
 
@@ -886,18 +894,13 @@ func newRPCTransaction(b *types.Block, txHash common.Hash) (*RPCTransaction, err
 
 // PublicTransactionPoolAPI exposes methods for the RPC interface
 type PublicTransactionPoolAPI struct {
-	b Backend
+	b         Backend
+	nonceLock *AddrLocker
 }
 
-// nonceMutex is a global mutex for locking the nonce while a transaction
-// is being submitted. This should be used when a nonce has not been provided by the user,
-// and we get a nonce from the pools. The mutex prevents the (an identical nonce) from being
-// read again during the time that the first transaction is being signed.
-var nonceMutex sync.RWMutex
-
 // NewPublicTransactionPoolAPI creates a new RPC service with methods specific for the transaction pool.
-func NewPublicTransactionPoolAPI(b Backend) *PublicTransactionPoolAPI {
-	return &PublicTransactionPoolAPI{b}
+func NewPublicTransactionPoolAPI(b Backend, nonceLock *AddrLocker) *PublicTransactionPoolAPI {
+	return &PublicTransactionPoolAPI{b, nonceLock}
 }
 
 func getTransaction(chainDb ethdb.Database, b Backend, txHash common.Hash) (*types.Transaction, bool, error) {
@@ -1176,17 +1179,6 @@ func submitTransaction(ctx context.Context, b Backend, tx *types.Transaction) (c
 // transaction pool.
 func (s *PublicTransactionPoolAPI) SendTransaction(ctx context.Context, args SendTxArgs) (common.Hash, error) {
 
-	if args.Nonce == nil {
-		// We'll need to set nonce from pool, and thus we need to lock here
-		nonceMutex.Lock()
-		defer nonceMutex.Unlock()
-
-	}
-
-	// Set some sanity defaults and terminate on failure
-	if err := args.setDefaults(ctx, s.b); err != nil {
-		return common.Hash{}, err
-	}
 	// Look up the wallet containing the requested signer
 	account := accounts.Account{Address: args.From}
 
@@ -1194,6 +1186,18 @@ func (s *PublicTransactionPoolAPI) SendTransaction(ctx context.Context, args Sen
 	if err != nil {
 		return common.Hash{}, err
 	}
+
+	if args.Nonce == nil {
+		// Hold the addresse's mutex around signing to prevent concurrent assignment of
+		// the same nonce to multiple accounts.
+		s.nonceLock.LockAddr(args.From)
+		defer s.nonceLock.UnlockAddr(args.From)
+	}
+
+	// Set some sanity defaults and terminate on failure
+	if err := args.setDefaults(ctx, s.b); err != nil {
+		return common.Hash{}, err
+	}
 	// Assemble the transaction and sign with the wallet
 	tx := args.toTransaction()
 
@@ -1270,14 +1274,12 @@ type SignTransactionResult struct {
 // The node needs to have the private key of the account corresponding with
 // the given from address and it needs to be unlocked.
 func (s *PublicTransactionPoolAPI) SignTransaction(ctx context.Context, args SendTxArgs) (*SignTransactionResult, error) {
-
 	if args.Nonce == nil {
-		// We'll need to set nonce from pool, and thus we need to lock here
-		nonceMutex.Lock()
-		defer nonceMutex.Unlock()
-
+		// Hold the addresse's mutex around signing to prevent concurrent assignment of
+		// the same nonce to multiple accounts.
+		s.nonceLock.LockAddr(args.From)
+		defer s.nonceLock.UnlockAddr(args.From)
 	}
-
 	if err := args.setDefaults(ctx, s.b); err != nil {
 		return nil, err
 	}
diff --git a/internal/ethapi/backend.go b/internal/ethapi/backend.go
index 42bf26613..68b5069d0 100644
--- a/internal/ethapi/backend.go
+++ b/internal/ethapi/backend.go
@@ -73,6 +73,7 @@ type State interface {
 }
 
 func GetAPIs(apiBackend Backend) []rpc.API {
+	nonceLock := new(AddrLocker)
 	return []rpc.API{
 		{
 			Namespace: "eth",
@@ -87,7 +88,7 @@ func GetAPIs(apiBackend Backend) []rpc.API {
 		}, {
 			Namespace: "eth",
 			Version:   "1.0",
-			Service:   NewPublicTransactionPoolAPI(apiBackend),
+			Service:   NewPublicTransactionPoolAPI(apiBackend, nonceLock),
 			Public:    true,
 		}, {
 			Namespace: "txpool",
@@ -111,7 +112,7 @@ func GetAPIs(apiBackend Backend) []rpc.API {
 		}, {
 			Namespace: "personal",
 			Version:   "1.0",
-			Service:   NewPrivateAccountAPI(apiBackend),
+			Service:   NewPrivateAccountAPI(apiBackend, nonceLock),
 			Public:    false,
 		},
 	}